16 Online Email APIs

There are a growing range of open web service APIs providing email-related services, whether that's for sending bulk emails, managing email marketing campaigns, validating email addresses, sending blog posts as emails or provisioning hosted email services. As of now, we have 16 email-related APIs listed here on ProgrammableWeb. Many of these are natural extensions of online email management and marketing services with APIs provided on a for-fee basis, usually on a sliding scale with pricing in buckets depending on number of emails sent. These can be quite profitable API platforms, with ExactTarget noting that they serve millions of API calls per month. For more, here's a rundown of the APIs in this segment:

ExactTarget API: Offers a suite of REST and SOAP APIs including ETBatch for bulk data transfer for large data sets ETScript for conditional behavior within an email, and Content Syndication to inject content from your site or content management system into ExactTarget emails. Note that most of their developer resources are password protected for members only.

FeedBlitz API: A service that can convert RSS feed and blog updates into email digests. They offer a REST-based API.

Google Provisioning API: Similar to above but more focused on the user setup function, this API provides a mechanism to programmatically create and manage Google Apps user accounts, nicknames, and email lists.

Email Address Validator API: Give this web service an email address and it will tell you if it's valid including domain and MX record check. From Dimple Software with online service provided by StrikeIron. Note that it is somewhat different in that it's implemented at a library for the .NET platform.

StrikeIron Email Verification API: Another StrikeIron service that checkes whether or not an email address actually exists or not without actually ever sending an email message.

Undisposable API: An interesting API that's intended to allow site owners to create a "collaborative protection system against disposable email addressing (DEA)." The idea is that it would prevent creation of user accounts based upon fake email addresses. REST-based.

Webmail.us API: Email hosting company (and division of Rackspace) offers an API with management and administration functions so "service providers are able to leverage the API to securely provision customer domains, mailboxes and related services in real-time using their own in-house systems [along with functions for] class-of-service controls for allotted storage space, number of mailboxes, spam filtering, and virus scanning settings."

WhatCounts API: Email management and service provider with both SOAP and REST APIs.

Yahoo Mail API: With the Yahoo! Mail Web Service APIs, you can build applications to perform tasks such as listing messages, displaying folders, and composing and sending messages. You can see our launch coverage here. The mashup below demonstrates using this web service along with the Flickr API and Greasemonkey to send postcards